1. Field of the Invention
The present invention relates to a log information management system for transmitting log information generated at an image forming apparatus to a server and managing the log information on the server, a control method therefor, and a storage medium.
2. Description of the Related Art
Hitherto, a log information management system has been utilized, which transmits log information generated at an image forming apparatus such as a digital copying machine and a printer to a server and manages logs on the server. With development of techniques for speeding up networks and of network security techniques, a server can be placed not on an intranet but on the Internet. In recent years, a service called a “cloud” has emerged, which enables utilizing computer resources on a large-scale datacenter connected to each server by necessary amounts. A server for managing logs can be placed on the cloud. Use of the cloud has various merits in eliminating needs for management of hardware and in easily adding resources according to a server load. On the other hand, types of log information to manage are diversified. A first type of log information is a job log. The job log is information concerning jobs, such as copy jobs, facsimile (FAX) jobs, and print jobs, performed by users, which is retained in an image forming apparatus. Servers can manage information concerning which of users performs jobs, how many jobs are performed, and the like by collecting job logs. A second type of log information is a device log. The device log is used to notify servers of various types of errors, e.g., remaining-amounts of consumables such as toner, and jams, at occurrence thereof, and to facilitate servicemen to take necessary countermeasures. A third type of log information is an image log. In recent years, image log checking systems have existed, which transmit, as image logs, image data that is, e.g., printed by image forming apparatuses and sent by FAXs. In such systems, the image logs transmitted to the servers can be checked visually and later by checkers. Checkers can check, e.g., whether any classified document is printed or transmitted to the outside.
Among the various types of logs cited above, the image logs are overwhelmingly large in log-size. The image log checking system cannot ignore traffic loads imposed on a communication network in addition to processing loads imposed on servers that receive logs. When the loads imposed on the network increases, communication efficiency of the entire network decreases. Sometimes, users' operations are adversely affected. Thus, the above image log checking system is enabled to set, as a time at which the image forming apparatus transmits an image log to a server, a night-time in which users don't use the network.
In a log information management system configured so that each image forming apparatus transmits log information to a server, a timing should be set, at which each image forming apparatus transmits log information to the server. Japanese Patent Application Laid-Open No. 2004-40630 discusses a technique in which usually, an image forming apparatus periodically transmits log information to a server and in which the server temporarily changes a log transmission interval by notifying the image forming apparatus of an interval at which the image forming apparatus transmits the next log information, as a response. Consequently, the server can designate, at a timing at which the image forming apparatus transmits a log, a timing of transmitting the next log.
In order to prevent an increase in a daytime network load, a night-time is often set as an image log transmission time by the log information management system for managing image logs on servers, as described above. However, when the number of image forming apparatuses to be managed is increased to hundreds or thousands, the problems of each server's processing load and a network processing load arise again. For example, if thousands of image forming apparatuses concurrently perform log transmissions at a specific time in a night, an associated-server's processing load drastically increases at the specific time. Many log transmissions fail. Retransmission of failed log transmissions is repeated. Accordingly, time taken to complete all log transmissions is increased. Thus, a situation may occur, in which the log transmissions are not completed until morning at which a user' s operation is started. In addition, an image forming apparatus having to be in an electric-power saving state except during each log transmission should be in a normal state in order to repeat the retransmission of the log. Consequently, a problem of wasted power consumption occurs.
The technique discussed in Japanese Patent Application Laid-Open No. 2004-40630 is based on a premise that an image forming apparatus periodically transmits a log to a server. Accordingly, the technique discussed therein cannot be applied to a case that an image forming apparatus transmits a log only when the log is generated.